max49017 - 1.7v, dual micropower comparator with built-in ... › en › ds › max49017.pdf ·...

General Description The MAX49017 is a space-saving, dual comparator with built-in voltage reference and push-pull output. The de-vice is AEC-Q100 qualified, which is ideal for automotive applications: car battery monitoring systems, infotainment head units, and ADAS modules. The MAX49017 is avail-able in an 8-pin, 2mm x 2mm TDFN package with side-wettable flanks. The device features a Beyond-the-Rails™ input, offers a supply voltage range from 1.7V to 5.5V, and consumes only 1.35μA of supply current. The device also features internal filtering to provide high RF immunity, important in automotive systems. The device has a built-in 1.252V reference that is factory trimmed to an initial accuracy of 1% and better than 2.5% over the entire temperature range. The reference output is stable for capacitive loads up to 100pF or above 0.1µF (with an unstable region from 100pF and 0.1µF). The MAX49017 is fully specified over -40°C to +125°C au-tomotive temperature range.

Applications ● Automotive

• Car Battery Monitoring Systems• ADAS

Benefits and Features ● microPower Operating Current (Total 1.35μA (Typ),

2.55μA (Max)) Preserves Battery Power● Internal Precision Reference Saves Space and Cost

of an External Reference● < 1% at Room Temperature, < 2.5% Over

Temperature Reference● Beyond-the-Rails Input Voltage Range = -0.2V to 5.7V● Supply Voltage Range (1.7V to 5.5V) Allows

Operation from 1.8V, 2.5V, 3V, and 5V Supplies● < 10μs Propagation Delay● Push-Pull Output● Tiny, 2mm x 2mm, 8-TDFN Package Saves Board

Space● Enable Automotive Safety Integrity Level

(ASIL) Compliance● AEC-Q100 Qualified, Refer to Ordering Information for

the List of /V PartsOrdering Information appears at end of data sheet.

Simplified Block Diagram

REFREF11.252V.252V

REF/INA-REF/INA-

INA+INA+

INB+INB+

INB-INB-

GNDGND

OUTAOUTA

OUTBOUTB

MAX49017MAX49017

VVDDDD

Beyond-the-Rails is a trademark of Maxim Integrated Products, Inc.

Click here for production status of specific part numbers.

MAX49017 1.7V, Dual microPower Comparatorwith Built-In Reference

EVALUATION KIT AVAILABLE

19-100578; Rev 0; 6/19

https://www.maximintegrated.com/en/storefront/storefront.html

Absolute Maximum Ratings VDD to GND .............................................................. -0.3V to +6V INA+, REF/INA-, INB+, INB- to GND ............ -0.3V to VDD + 0.3V OUTA, OUTB to GND ................................... -0.3V to VDD + 0.3V Comparator Output Short Circuit Current Duration .................10s Reference Output Short-Circuit Current Duration .......... Indefinite Continuous Current Into/Out of Any Input Pin ..................... 20mA Continuous Current Into/Out of Any Output Pin .................. 50mA

Continuous Power Dissipation (TA = +70°C), Multilayer Board TDFN (derate 9.8mW/°C above 70°C) ..........................784mW

Operating Temperature Range ...........................-40°C to +125°C Junction Temperature (TJMAX). ........................................+150°C Storage Temperature Range ..............................-65°C to +150°C Lead Temperature (soldering, 10s) ...................................+300°C Soldering Temperature (reflow) ........................................+260°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Package Information

TDFN-8 Package Code T822Y+3C Outline Number 21-100185 Land Pattern Number 90-100070 Thermal Resistance, Single-Layer Board: Junction-to-Ambient (θJA) 130°C/W Junction-to-Case Thermal Resistance (θJC) 8°C/W Thermal Resistance, Multilayer Board: Junction-to-Ambient (θJA) 102°C/W Junction-to-Case Thermal Resistance (θJC) 8°C/W

For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.


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https://pdfserv.maximintegrated.com/land_patterns/90-100070.PDF

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http://www.maximintegrated.com/thermal-tutorial

http://www.maximintegrated.com/thermal-tutorial

Electrical Characteristics (VDD = 3.3V, VCM = 1.25V, TA = -40°C to +125°C. Typical values are at TA = +25°C, unless otherwise noted. (Note 1))

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY VOLTAGE VDD Supply Voltage Range VDD Guaranteed by PSRR specification 1.7 5.5 V

VDD Supply Current IDD No output or reference load current, TA = -40°C to +125°C 1.35 2.55 μA

Power-Up Time 5 μs COMPARATOR

Input Common-Mode Voltage Range VCM

TA = +25°C -0.2 VDD + 0.2 V

TA = -40°C to +125°C 0 VDD

Input Offset Voltage VOS

VCM = 0V to VDD -1V (Note 2) 8

mV VCM = VDD -1 to VDD, TA = 0°C to +85°C (Note 2) 10

VCM = VDD -1 to VDD, TA = -40°C to +125°C (Note 2) 14

Input Offset Drift 27 μV/°C Input Hysteresis VHYS (Note 3) 2.5 mV

Input Bias Current

VCM = -0.2V to VDD +0.2V, TA = +25°C 2 5

nA VCM = 0V to VDD, TA = -40°C to +85°C 5 VCM = 0.2V to VDD, TA = -40°C to +125°C 5

Input Offset Current 5 nA Input Capacitance Either input, over VCM range 2 pF Power Supply Rejection Ratio PSRR DC, over the entire common mode input

voltage range 50 dB

Common Mode Rejection Ratio CMRR DC, over the entire common mode input

voltage range 46 dB

Output Voltage Swing Low VOL

Sinking 2mA output current, VOUT - VGND

0.4 V

Output Voltage Swing High VOH

Sourcing 2mA output current, VDD - VOUT

0.4 V

Propagation Delay (Note 4) tPD

100mV overdrive, output low-to-high 9.6

μs 100mV overdrive, output high-to-low 3.2 20mV overdrive, output low-to-high 9.9 20mV overdrive, output high-to-low 5.2

Rise Time tR 25% to 75%, CL = 15pF 300 ns Fall Time tF 75% to 25%, CL = 15pF 52 ns INTERNAL REFERENCE VOLTAGE

Reference Voltage VREF TA = -40°C to +125°C 1.21875 1.25 1.28125

V TA = +25°C 1.2375 1.25 1.2625



Electrical Characteristics (continued) (VDD = 3.3V, VCM = 1.25V, TA = -40°C to +125°C. Typical values are at TA = +25°C, unless otherwise noted. (Note 1))

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Reference Thermal Drift VREF-TEMPCO Over extended temperature range, TA = -40°C to +125°C 15 ppm/°C

Line Regulation 1200 ppm/V Load Regulation IVREFOUT = ±100nA 0.01 mV/nA Output Current (Note 5) 0.1 μA

Voltage Noise 0.1 to 10Hz 82 μVP-P 10Hz to 10kHz 100 μVRMS

Note 1: All specifications are 100% production tested at TA = +25°C. Specification limits over temperature (TA = TMIN to TMAX) are guaranteed by design, not production tested.

Note 2: Input offset voltage; VOS is defined as the center of the hysteresis band or average of the threshold trip points. Note 3: The hysteresis-related trip points are defined as the edges of the hysteresis band, measured with respect to the center of the

band (i.e., VOS) (Figure 1). Note 4: Specified with an input overdrive (VOVERDRIVE) of 100mV and 20mV, and load capacitance of CL = 15pF. VOVERDRIVE is

defined above the offset voltage and hysteresis of the comparator input. The reference voltage error should also be added. Note 5: Guaranteed by Load Regulation.



Typical Operating Characteristics (VDD = 3.3V, TA = +25°C, unless otherwise noted.)



Typical Operating Characteristics (continued) (VDD = 3.3V, TA = +25°C, unless otherwise noted.)



Pin Configuration

8 TDFN

8

7

6

5

1

2

3

4

REF/INA-

INA+

INB+

INB-

GND

OUTA

OUTB

VDD

MAX49017MAX49017

TOP VIEW

2mm x 2mm

+

Pin Description PIN NAME FUNCTION

1 OUTA Comparator A Output

2 REF/INA- Internal Reference Output. Internally connected to the inverting input of comparator A. Bypass REF pin with a 0.1µF capacitor to GND as close as possible to the device.

3 INA+ Comparator A Noninverting Input 4 GND Ground 5 INB+ Comparator B Noninverting Input 6 INB- Comparator B Inverting Input. A 3.3nF capacitor is optional to be added at INB-. 7 OUTB Comparator B Output 8 VDD VDD Supply Voltage. Bypass VDD with a 0.1μF capacitor to GND as close as possible to the device pin. — EP Exposed Pad. Connect EP to GND.



Detailed Description The MAX49017 features a built-in 1.252V reference that is factory trimmed to an initial accuracy of 1% and better than 2.5% over the entire temperature range. The common mode voltage range of this family extends 200mV beyond the rails, allowing signals slightly beyond the rails to trigger the comparator. The 2.5mV internal hysteresis ensures clean output switching even with slow moving input signals. Large internal output drivers allow rail-to-rail output swing with up to ±2mA loads. The output stage employs a unique design that minimizes supply current surges while switching, virtually eliminating supply glitches typical of many other comparators. The MAX49017 has a push-pull output stage that sinks as well as sources current.

Input Stage Circuitry The input common-mode voltage range extends from - 0.2V to VDD + 0.2V. The comparator operates at any differential input voltage within these limits. Input bias current is typically ±1nA if the input voltage is between the supply rails. Comparator inputs are protected from overvoltage by internal ESD protection diodes connected to the supply rails. As the input voltage exceeds the supply rails, these ESD protection diodes become forward biased and begin to conduct increasing input bias current (see the Input Bias Current vs. Input Common Mode Voltage and Input Bias Current vs. Input Differential Voltage graph in the Typical Operating Characteristics).

Output Stage Structure The device contains a unique break-before-make output stage capable of rail-to-rail operation with up to ±2mA loads. Many comparators consume orders of magnitude more current during switching than during steady-state operation. In the Typical Operating Characteristics, the Supply Current vs. Output Transition Frequency graphs show the minimal supply-current increase as the output switching frequency approaches 1kHz. This characteristic reduces the need for power-supply filter capacitors to reduce glitches created by comparator switching currents. In automotive applications, this characteristic results in a substantial increase in car battery life.

Voltage Reference The MAX49017 comes with an internal voltage reference that has initial accuracy of ±1%. The device’s internal reference has a typical temperature coefficient of 15ppm/°C over the full -40°C to +125°C temperature range. The reference is a very-low-power bandgap cell, with a maximum 10kΩ output impedance. REF pin can source and sink up to 100nA to external circuitry. For applications that need increased drive, buffer REF with a low input-bias current op amp such as the MAX44265. Internal reference voltage of MAX49017 is stable with capacitive load of 0pF to 100pF and values greater than 0.1µF (with an unstable region from 100pF to 0.1µF). To minimize unwanted feedback from pin OUTA to REF pin through package parasitics, an 0.1µF bypass cap is recommended to be added on the REF pin.



Figure 1. Hysteresis Band

Applications Information

Internal Hysteresis Many comparators oscillate in the linear region of operation because of noise or undesired parasitic feedback. This tends to occur when the voltage on one input is equal or very close to the voltage on the other input. The MAX49017 has internal 2.5mV hysteresis to counter parasitic effects and noise. The hysteresis in a comparator creates two trip points: one for upper threshold (VTRIP+) and one for lower threshold (VTRIP-) for voltage transitions on the input signal (Figure 1). The difference between the trip points is the hysteresis band (VHYS). When the comparator’s input voltages are equal, the hysteresis effectively causes one comparator input to move quickly past the other, thus taking the input out of the region where oscillation occurs. Figure 1 illustrates the case in which IN_- has a fixed voltage applied, and IN_+ is varied. If the inputs were reversed, the figure would be the same, except with an inverted output.



Adding External Hysteresis In applications requiring more than the internal 2.5mV hysteresis of the devices, additional hysteresis can be added with two external resistors. Since these comparators are intended to use in very low-power systems, care must be taken to minimize power dissipation in the additional circuitry. Regardless of which approach is employed to add external hysteresis, the external hysteresis will be VDD dependent. Figure 2 shows the simplest circuit for adding external hysteresis. In this example, the hysteresis is defined by:

Hysteresis =RGRF

x VDD

Where RG is the source resistance and RF is the feedback resistance. The comparison threshold is VREF.

REF/INA-REF/INA-

INA+INA+

INB+INB+

INB-INB-

OUTAOUTA

OUTBOUTB

MAX49017MAX49017

VVDDDD

RRGG RRFFVVININ++

Figure 2. External Hysteresis on MAX49017



Component Selection Because the MAX49017 is intended for very low power-supply systems, the highest impedance circuits should be used wherever possible. The offset error due to input-bias current is proportional to the total impedance seen at the input. For example, selecting components for Figure 2, with a target of 50mV hysteresis, a 5V supply, and choosing an RF of 10MΩ gives RG as 100kΩ. The total impedance seen at IN+ is therefore 10MΩ || 100kΩ, or 99kΩ. The typical Input bias current of MAX49017 is 2nA; therefore, the error due to source impedance is less than 200μV.

Board Layout and Bypassing Power-supply bypass capacitors are not typically needed, but use 100nF bypass capacitors close to the device’s supply pins when supply impedance is high, supply leads are long, or excessive noise is expected on the supply lines. Minimize signal trace lengths to reduce stray capacitance. A ground plane and surface-mount components are recommended. If the REF pin is decoupled, use a new low-leakage capacitor.

Window Detector The MAX49017 is ideal for window detectors (undervoltage/overvoltage detectors). The Typical Application Circuit shows how a window detector circuit can detect the related car battery's voltage level with an undervoltage of 2.9V and an overvoltage of 4.2V. Choose different thresholds by changing the values of R1, R2, and R3. OUTA provides an active-low undervoltage indication, and OUTB provides an active-low overvoltage indication.

The design procedure is as follows:

1. Select R1. The input bias current into INB- is normally less than 5nA, so the current through R1 should exceed 250nA for the thresholds to be accurate. In this example, choose R1 = 0.25MΩ (1.252V/5µA).

2. Calculate R2 + R3. The overvoltage threshold should be 4.2V when VIN is rising. The design equation is as follows:

R2 + R3 = R1x[[ VOTHVREF + VHYS ] − 1] = 250kΩx[[ 4.2V

1.252V + 0.0025V ] − 1] = 0.587MΩ

3. Calculate R2. The undervoltage threshold should be 2.9V when VIN is falling. The design equation is as follows:

R2 = (R1 + R2 + R3)x(VREF − VHYSVUTH ) − R1 = 0.837MΩx(1.252V − 0.0025V

2.9V ) − 0.25MΩ = 0.111MΩ

4. Calculate R3:

R3 = (R2 + R3) − R2 = 0.587MΩ − 0.111MΩ = 0.476MΩ

5. Choose standard 1% resistors for R1 = 249kΩ, R2 = 110kΩ, and R3 = 475kΩ. 6. Verify the resistor values. The equations are as follows, evaluated for the above example.

Overvoltage threshold: VOTH = (VREF + VHYS)x (R1 + R2 + R3)

R1 = 4.20V

Undervoltage threshold: VUTH = (VREF − VHYS)x (R1 + R2 + R3)

(R1 + R2) = 2.897V where the internal hysteresis band, VHB is 2.5mV.



Typical Application Circuit

R3

R2

R1

REF/INA-

REF1.252V

GND

VIN

INA+

INB+

INB-

VOTH = 4.2VVUTH = 2.9V

VDD

5V

GND

OUTA

OUTB

C1

C2

NOTE: NOTE: C2 = 3.3nf IS OPTIONAL TO BE ADDED AT INB- TO MINIMIZE PARASITIC FEEDBACK.

MAX49017MAX49017

UNDERVOLTAGE

OVERVOLTAGE

Ordering Information PART NUMBER TEMPERATURE RANGE PIN-PACKAGE TOP MARK

MAX49017ATA/VY+T -40°C to +125°C 8-TDFN +BSX

+Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. /V Denotes an automotive qualified part. Y = Side-wettable package.



Revision History REVISION NUMBER

REVISION DATE DESCRIPTION PAGES

CHANGED 0 6/19 Initial release —

For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.


Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2019 Maxim Integrated Products, Inc.

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